If it will not go into gear you have probably missinstalled one of the filters.
6 quarts transmission fluid
You have to remove the pan to drain the fluid.
its ethier transmission or 75w90 fluid you need to call dodge and ask
change both filters and be sure both are tight
Mopar ATF+4
Same place you check the fluid level.
through the filler tube
Mopar ATf+4
Where I work it costs $99.00.
12-15 quarts
Mopar ATF+4
4 quarts.